1. Field of the Invention
The present invention relates to a transcatheter occluding implant for portion of a vessel lumen. Generally speaking, these implants comprise a plug for siting in the lumen and collapsible for transfer to its position in the lumen and include means for retaining the plug in the lumen.
There are numerous circumstances when there is a requirement to occlude a vessel in the treatment of medical conditions ranging from critical care applications to cosmetic applications. This invention relates to products for use in the occlusion of vessels in the human body.
2. Background Information
Conventionally vessels are occluded using coil devices. Coils are metallic based devices and typically consist of a metal wire wound into a helical spring. This length of spring however, has the property of being able to coil up into various pre-set shapes in order to occlude the vessel. Coils are used in a whole range of applications such as arterial and venous embolization, embolization of selective vessel supply to tumours, arterio-venous malformations, embolization of aneurysms and male sterilisation. Coils are unsuitable for closure of varicose veins, varicoceles and other similar venous applications due to the high level of collateral flow in the venous circulation.
A typical example of a device consisting of a wire for occluding an aperture within a body surface such as an arterial and ventricular septal defects is described in U.S. Pat. No. 5,108,420 (Marks).
Patent Ser. No. WO 92/19162 (Seld) shows a surgical implantation device to be placed within a patient's body and seal a herneal rupture in the abdominal fascia. Essentially, this consists of a annular support large enough to cover the opening and a plug which is placed through the opening. Similarly, patent Ser. No WO 97/41778 (Gilson) discloses a transcatheter occluder device which usually has a pair of spaced-apart annular supports interconnected by a narrow neck portion extending between the annular supports. The device is formed by a highly compressible foam plastics material and by virtue of its geometry, includes an opening, the neck siting in the defect opening while the annular supports remain on opposite sides of the opening. This device depends on its physical geometry for use in occlusion of holes. It is necessary that it engages and overlaps the side wall of the occlusion and is thus anchored by engagement with a peripheral face defining the opening.
Very often, vascular vessels need to be blocked. These vessels by the very nature of their anatomy can be described as lubricious tubes providing a very slippy environment and thus stabilising an occlusive device in such a vessel lumen can be extremely difficult. A further problem associated with such vessels is that they can have an indigenous pulse within the arterial wall. Such a pulse can be transmitted along the entire length of the vessel and against any occluding implant mounted therein. Further, by the very nature of the change in pressure within the vessel, the vessel, for example, will often expand and contract and there is thus a need for an implant that will be able to accommodate the changes in the bore of the vessel lumen in which it is placed.